Nevada casinos and the state government are making a killing off unclaimed gambling winnings.

Ever since Nevada slots and video lottery terminals began issuing paper tickets instead of spitting out actual coins, gamblers have literally been leaving millions of dollars unclaimed. Some of these tickets are presumably lost or left behind in the machine by accident, while others are for minor amounts that the gamblers apparently feel isn’t worth the time or effort required to redeem the tickets at the casino cage.

According to figures compiled by the Las Vegas Sun, nearly $12m worth of winning tickets was left behind in fiscal 2016, with Las Vegas Strip casinos accounting for over $7m of that total.

Under a Nevada law passed in 2011, the tickets are only valid for a period of 180 days or a fixed date established by an individual casino, whichever is sooner. Three-quarters of the unclaimed vouchers are redirected into the state’s general fund, while the casinos keep the remaining 25%.